探討台灣西海岸環境變化對養殖牡蠣中砷累積量之影響   全文下載

Accumulation of Arsenic in Pacific Oysters, Crassostrea gigas, Collected from Aquaculture Sites in Western Taiwan

本研究以連續式氧化器連結原子吸收光譜儀，分析牡蠣中砷元素的含量，不同的季節，分別在台灣西海岸不同的牡蠣養殖場採集樣本後進行分析工作。牡蠣中總砷的乾基含量介於8.83-19.51 mg／kg，整體平均值為13.7 ± 2.2 mg／kg。變異數分析結果顯示，不同地區之牡蠣的砷含量並未顯示顯著性的差異。排除香山之分析數據，節性變化則顯示累積雨量與牡蠣中的砷含量呈現指數型的相關性，因此推論牡蠣養殖區之環境中的砷含量，為控制牡蠣中砷富集的因子。以無機砷物種的含量評估食用台灣西海岸牡蠣中的致癌風險機率為4.2 × 10-6，約為美國環境保護署訂定之可接受值的四倍。

Oyster, farmed inland on the west coast of Taiwan, can provide a good indication of pollution levels in aqua environments, which may be affected by upland watershed, industrial and municipal waste water discharge, precipitation and local runoff. Using a continuous flow-hydride generation-atomic absorption technique, this study measured arsenic concentrations in Pacific oysters (Crassostrea gigas) collected from several aquaculture sites along the west coast of Taiwan over different seasons. The arsenic concentrations ranged between 8.83 and 19.51 mg/kg dry wt. (mean 13.7 ± 2.2 mg/kg). Excluding Hsianshan, a suspected source of toxin, it was possible to create an exponential decay model between the arsenic content in oyster and accumulated precipitation. We found the lifetime cancer risk associated with the inorganic arsenic in oysters to be 4.2 × 10-6, which is 4 times higher than what is considered acceptable by the U.S. Environmental Agency.